X-Ray Physics Review part 1 Flashcards Preview

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Flashcards in X-Ray Physics Review part 1 Deck (28)
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1
Q

What is the SI unit equivalent for REM (Radiation Equivalent Man)?

A

Seivert

2
Q

What units of measure account for differences in biologic tissue?

A

REM or Seivert

3
Q

What is the SI unit for Roentgen (R)?

A

c/Kg or coulombs per kilogram

4
Q

What unit is used to measure exposure in air?

A

the Roentgen (R) or coulombs per kilogram (c/Kg)

5
Q

What does LET stand for?

A

Linear Energy Transfer

6
Q

What does LET measure?

A

The amount of energy transferred to tissue per unit path length traveled in that tissue.

7
Q

What does RBE stand for?

A

Relative Biological Effectiveness

8
Q

As LET increases RBE _____

A

increases

9
Q

As RBE increases biological damage _____

A

increases

10
Q

What is the purpose of “Quality Factor (QF)” ratings of different types of radiation?

A

To be able to compare different types of radiations ability to produce biologic damage. Ie. alpha particles have a very high let and so have a high QF of 20. Xrays have a low LET and so have a low QF of 1.

11
Q

Where is Equivalent Dose used and in what units is it expressed?

A

It is used to report doses on radiation safety reports (in REM or Seiverts) and attempt to take in to account radiation damage from multiple sources

12
Q

What (biological thing) does Effective Dose Equivalent take into account?

A

The sensitivity of the different organs to determine the overall harm done

13
Q

How many rad to a Gray?

A

there are 100 rads in a Gray. rad/100 = Gray

14
Q

How many rem to a Seivert?

A

There are 100 rem in a Seivert. rem/100 = Seivert

15
Q

The unit of does equivalent is the ____

A

REM (Radiation Equivalent Man)

16
Q

What uses organ weighting factors to determine the risk of radiation induced cancer?

A

Effective dose equivalent

17
Q

What units are used to report occupational dose?

A

REM or Seiverts

18
Q

What does ALARA stand for?

A

As Low As Reasonably Acheivable

19
Q

No does is a ____ dose

A

safe

20
Q

What is the occupational worker effective does limit (annual)?

A

50 mSv or 5 rem

21
Q

What is the public exposure limit (annual)?

A

1 mSv or 0.1 rem

22
Q

Are stochastic effects guaranteed to happen?

A

No, there is only a probablility that they might occur. Also, not a direct relationship - ie. cancer or genetic effects

23
Q

What is the relationship between Non-stochastic effects and absorbed dose?

A

Non-stochastic effects (ie. erythema, cataracts, desquamation) increase in severity with absorbed dose.

24
Q

Is Direct effect or Indirect effect responsible for the production of free radicals?

A

Indirect Effect

25
Q

What is a molecular product produced via the radiolysis of water that is toxic to the cell?

A

Hydrogen peroxide

26
Q

Between Interphase and mitosis, which is the most radiosensitive?

A

Mitosis

27
Q

What are the cardinal rules of radiation protection

A

Time, Distance, Shielding

28
Q

How does collimation improve radiographic contrast?

A

by reducing scatter